Air Gear (The art is gorgeous!! Best drawn action series)Nana (Ai Yazawa is soo talented )H2O (I read this one recently and the art's really pretty, especially the girls )Veritas (best drawn martial arts manga ever and Vera and Madoka are drawn beautifully) Rockin' Heaven (Just another of my favourites. )Katekyo Hitman Reborn Bakuman ( Takeshi Obata is one of the best artist out there)

Naruto (the art is not bad but isn't really great either and it has really dropped quite a few notches in the recent chapters but unlike many other shounen manga, Naruto's art is clear like in, you can actually understand the action panels)

bleach(i agree, his backgrouns nowadays suck, but he makes up for it with his amazingly detailed character expressions)
dgrayman ( love her backgrounds)
neon genesis evangelion by sadamoto
spice and wolf
inuyasha